Rope sway detection and mitigation for elevator system

Abstract

A rope sway detection system of an elevator system includes a magnetic pickup located adjacent to a suspension member of an elevator system. The magnetic pickup is configured to detect a movement of the suspension member via a change in a magnetic field at the magnetic pickup. A signal processing unit is operably connected to the magnetic pickup. The signal processing unit is configured to determine a maximum amplitude of a sway of the suspension member based on the change in the magnetic field, compare the maximum amplitude to a preselected threshold, and signal a change in operation of the elevator system based on an actual or predicted exceedance of the threshold.

What is claimed is: 
     
         1 . A rope sway detection system of an elevator system, comprising:
 a magnetic pickup disposed adjacent to a suspension member of an elevator system, the magnetic pickup configured to detect a movement of the suspension member via a change in a magnetic field at the magnetic pickup; and   a signal processing unit operably connected to the magnetic pickup, the signal processing unit configured to:
 determine a maximum amplitude of a sway of the suspension member based on the change in the magnetic field; 
 compare the maximum amplitude to a preselected threshold; and 
 signal a change in operation of the elevator system based on an actual or predicted exceedance of the threshold. 
   
     
     
         2 . The rope sway detection system of  claim 1 , further comprising two or more magnetic pickups disposed at the hoistway, at some angle apart relative to a rope central axis. 
     
     
         3 . The rope sway detection system of  claim 1 , wherein the magnetic pickup is selectably retractable. 
     
     
         4 . The rope sway detection system of  claim 1 , further comprising a power driver operably connected to the magnetic pickup. 
     
     
         5 . The rope sway detection system of  claim 4 , wherein the power driver and the magnetic pickup are configured to emit an actuation signal to disrupt sway of the suspension member. 
     
     
         6 . The rope sway detection system of  claim 4 , wherein the power driver and the magnetic pickup are configured to emit a holding signal to attract the suspension member to the magnetic pickup. 
     
     
         7 . An elevator system comprising:
 a hoistway;   an elevator car disposed in the hoistway;   a suspension member operably connected to the elevator car to move the elevator car along the hoistway; and   a rope sway detection system disposed in the hoistway, including:
 a magnetic pickup disposed adjacent to the suspension member, the magnetic pickup configured to detect a movement of the suspension member via a change in a magnetic field at the magnetic pickup; and 
 a signal processing unit operably connected to the magnetic pickup, the signal processing unit configured to:
 determine a maximum amplitude of a sway of the suspension member based on the change in the magnetic field; 
 compare the maximum amplitude to a preselected threshold; and 
 signal a change in operation of the elevator system based on an actual or predicted exceedance of the threshold. 
 
   
     
     
         8 . The elevator system of  claim 7 , further comprising two or more magnetic pickups disposed at the hoistway, at some angle apart relative to a rope central axis. 
     
     
         9 . The elevator system of  claim 7 , wherein the magnetic pickup is selectably retractable. 
     
     
         10 . The elevator system of  claim 7 , further comprising a power driver operably connected to the magnetic pickup. 
     
     
         11 . The elevator system of  claim 10 , wherein the power driver and the magnetic pickup are configured to emit an actuation signal to reduce sway of the suspension member. 
     
     
         12 . The elevator system of  claim 10 , wherein the power driver and the magnetic pickup are configured to emit a holding signal to attract the suspension member to the magnetic pickup. 
     
     
         13 . The elevator system of  claim 7 , wherein the magnetic pickup is disposed at or near a drive sheave of the elevator system. 
     
     
         14 . The elevator system of  claim 7 , wherein the suspension member is a rope formed from a plurality of metallic wires. 
     
     
         15 . The elevator system of  claim 7 , wherein the rope sway detection system is configured to sense one or more of speed of the elevator car, operational frequency of an elevator drive, load sensing of the elevator car, or relative suspension member tension. 
     
     
         16 . A method of detecting movement of a suspension member of an elevator system, comprising:
 positioning a magnetic pickup adjacent to the suspension member;   sensing a change in a magnetic field of the magnetic pickup indicative of movement of the suspension member; and   determining a maximum amplitude of the movement based on the change in the magnetic field.   
     
     
         17 . The method of  claim 16 , further comprising:
 comparing the maximum amplitude to a predetermined threshold; and   changing operation of the elevator system based on an actual or predicted exceedance of the threshold.   
     
     
         18 . The method of  claim 16 , further comprising transmitting an actuation signal from the magnetic pickup toward the suspension member to reduce movement of the suspension member. 
     
     
         19 . The method of  claim 16 , further comprising emitting a holding signal from the magnetic pickup to attract the suspension member to the magnetic pickup to reduce movement of the suspension member. 
     
     
         20 . The method of  claim 16 , further comprising sensing one or more of speed of an elevator car, operational frequency of an elevator drive, load sensing of the elevator car and/or relative suspension member tension via the magnetic pickup.